[profile] in-process mergeing support (part-2)

(Part-1 merging API is in profile runtime)

This patch implements a portable file opening API
with exclusive access for the process. In-process
profile merge requires profile file update to be
atomic/fully sychronized.




git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@271864 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 1 deletions

diff --git a/lib/profile/InstrProfilingUtil.c b/lib/profile/InstrProfilingUtil.c
index eb79d4222..24e302d4a 100644
--- a/lib/profile/InstrProfilingUtil.c
+++ b/lib/profile/InstrProfilingUtil.c
@@ -12,9 +12,15 @@
 
 #ifdef _WIN32
 #include <direct.h>
+#include <windows.h>
 #else
 #include <sys/stat.h>
 #include <sys/types.h>
+#if defined(__linux__)
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
 #endif
 
 #ifdef COMPILER_RT_HAS_UNAME
@@ -35,7 +41,7 @@ void __llvm_profile_recursive_mkdir(char *path) {
 #ifdef _WIN32
     _mkdir(path);
 #else
-    mkdir(path, 0755);  /* Some of these will fail, ignore it. */
+    mkdir(path, 0755); /* Some of these will fail, ignore it. */
 #endif
     path[i] = save;
   }
@@ -70,4 +76,51 @@ int lprofGetHostName(char *Name, int Len) {
 }
 #endif
 
+FILE *lprofOpenFileEx(const char *ProfileName) {
+  FILE *f;
+  int fd;
+#ifdef COMPILER_RT_HAS_FCNTL_LCK
+  struct flock s_flock;
+
+  s_flock.l_whence = SEEK_SET;
+  s_flock.l_start = 0;
+  s_flock.l_len = 0; /* Until EOF.  */
+  s_flock.l_pid = getpid();
+
+  s_flock.l_type = F_WRLCK;
+  fd = open(ProfileName, O_RDWR | O_CREAT, 0666);
+  if (fd < 0)
+    return 0;
+
+  while (fcntl(fd, F_SETLKW, &s_flock) && errno == EINTR)
+    continue;
+
+  f = fdopen(fd, "r+b");
+#elif defined(_WIN32)
+  HANDLE h = CreateFile(ProfileName, GENERIC_READ | GENERIC_WRITE, 0, 0,
+                        OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
+  if (h == INVALID_HANDLE_VALUE)
+    return 0;
+
+  fd = _open_osfhandle((intptr_t)h, 0);
+  if (fd == -1) {
+    CloseHandle(h);
+    return 0;
+  }
+
+  f = _fdopen(fd, "r+b");
+  if (f == 0) {
+    CloseHandle(h);
+    return 0;
+  }
+#else
+  /* Worst case no locking applied.  */
+  PROF_WARN("Concurrent file access is not supported : %s\n", "lack file locking");
+  fd = open(ProfileName, O_RDWR | O_CREAT, 0666);
+  if (fd < 0)
+    return 0;
+  f = fdopen(fd, "r+b");
+#endif
 
+  return f;
+}